Working overtime links to higher risk of stroke, heart disease

“It is plausible that there could be a causal relationship behind the link as sudden death following long working hours is often caused by stroke, due to long and repeated periods of stress, although that was not demonstrated in this study”. These studies provided data on 528,908 men and women who had 1722 strokes during an average follow-up of 7.2 years and 603,838 who had 4768 coronary events during an average 8.5 years of follow-up.

Kivimaki said in the final analysis they found a 13 per cent increased risk of incident coronary heart disease, in people working 55 hours, or more per week, compared with those putting in a normal 35 to 40 hour week. The results were adjusted to account for the age, gender and socioeconomic status of each study volunteer as well as factors such as smoking history, alcohol consumption and body mass index.

The risk of stroke was elevated 33% in people who worked 55 or more hours per week compared with those who worked 35 to 40 hours per week, and this was highly statistically significant (p=0.002).

“The pooling of all available studies on this topic allowed us to investigate the association between working hours and cardiovascular disease risk with greater precision than has previously been possible”, Kivimaki said in a statement.

Given the results, the researchers, therefore, advised doctors to take special care in diagnosing for heart problems in those known to work for long stretches of time. For starters, people who spend more time behind a desk have less time to be physically active. Aside from stress and physical toll, longer work hours can increase the risk of stroke among employees.

Kivimaki admitted that the researchers are only in the initial stages of comprehending what exactly is responsible for increasing stroke risk in people working long hours.

Working longer hours during the week could significantly increase chances of having a stroke, a new study suggests.

Among developed countries, Janlert noted, Turkey has the highest proportion of individuals working more than 50 hours a week (43 percent), and the Netherlands the lowest (less than 1 percent).

Some work conditions might be hard to change, such as underground work, climate conditions, and toxic exposure, Janlert said, “but the length of a working day is a human decision”.